The deleterious effects of undue radiation exposure to human and other life forms have necessitated the widespread utilization of passive low level radiation detection devices, such as thermo luminescent dosimeters (TLDs) and film type badges worn by individuals whose spheres of daily activity may expose them to ionizing radiation, such as workers in nuclear power plants or other radiation producing or utilizing facilities. Such passive radiation detection devices conventionally function to provide a visual indicia of the quantum of radiation exposure independent of the nature and location of the source thereof. Other types of radiation detectors, such as portable Geiger counters and the like are conventionally employed to locate the sources and intensity of emitted radiation. Neither of the foregoing types of device are of practical utility for making precision radiation surveys in low intensity radiation fields of complex geometry and elucidating the relative contributions of sources within said complex geometries such as those encountered in nuclear power or other radiation producing or utilizing facilities or where a need exists to maintain radiation doses to personnel as low as reasonably achievable.